+/*
+ * addrfam.c
+ * - address-family specific code
+ */
+/*
+ * This file is part of adns, which is
+ * Copyright (C) 1997-2000,2003,2006 Ian Jackson
+ * Copyright (C) 1999-2000,2003,2006 Tony Finch
+ * Copyright (C) 1991 Massachusetts Institute of Technology
+ * (See the file INSTALL for full details.)
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2, or (at your option)
+ * any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software Foundation,
+ * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ */
+
+#include <stdlib.h>
+#include <errno.h>
+#include <limits.h>
+#include <unistd.h>
+
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <netinet/in.h>
+#include <arpa/inet.h>
+
+#include "internal.h"
+
+/*
+ * General address-family operations.
+ */
+
+#define SIN(sa) ((struct sockaddr_in *)(sa))
+#define CSIN(sa) ((const struct sockaddr_in *)(sa))
+
+#define SIN6(sa) ((struct sockaddr_in6 *)(sa))
+#define CSIN6(sa) ((const struct sockaddr_in6 *)(sa))
+
+/* This gadget (thanks, Richard Kettlewell) makes sure that we handle the
+ * same set of address families in each switch. */
+#define AF_CASES(pre) \
+ case AF_INET: goto pre##_inet; \
+ case AF_INET6: goto pre##_inet6
+
+static void unknown_af(int af) {
+ fprintf(stderr, "ADNS INTERNAL: unknown address family %d\n", af);
+ abort();
+}
+
+#define IN6_ADDR_EQUALP(a, b) \
+ (!memcmp((a).s6_addr, (b).s6_addr, sizeof((a).s6_addr)))
+
+int adns__genaddr_equal_p(int af, const union gen_addr *a,
+ int bf, const void *b) {
+ const union gen_addr *bb= b;
+ if (af != bf) return 0;
+ switch (af) {
+ AF_CASES(af);
+ af_inet: return a->v4.s_addr == bb->v4.s_addr;
+ af_inet6: return IN6_ADDR_EQUALP(a->v6, bb->v6);
+ default: unknown_af(af); return -1;
+ }
+}
+
+int adns__sockaddr_equal_p(const struct sockaddr *sa,
+ const struct sockaddr *sb) {
+ if (sa->sa_family != sb->sa_family) return 0;
+ switch (sa->sa_family) {
+ AF_CASES(af);
+ af_inet: {
+ const struct sockaddr_in *sina= CSIN(sa), *sinb= CSIN(sb);
+ return (sina->sin_addr.s_addr == sinb->sin_addr.s_addr &&
+ sina->sin_port == sinb->sin_port);
+ }
+ af_inet6: {
+ /* Don't check the flowlabel. That's apparently useful for routing
+ * performance, but doesn't affect the address in any important
+ * respect. */
+ const struct sockaddr_in6 *sin6a= CSIN6(sa), *sin6b= CSIN6(sb);
+ return (IN6_ADDR_EQUALP(sin6a->sin6_addr, sin6b->sin6_addr) &&
+ sin6a->sin6_port == sin6b->sin6_port &&
+ sin6a->sin6_scope_id == sin6b->sin6_scope_id);
+ }
+ default:
+ unknown_af(sa->sa_family);
+ return -1;
+ }
+}
+
+int adns__addr_width(int af) {
+ switch (af) {
+ AF_CASES(af);
+ af_inet: return 32;
+ af_inet6: return 128;
+ default: unknown_af(af); return -1;
+ }
+}
+
+void adns__prefix_mask(int af, int len, union gen_addr *mask_r) {
+ switch (af) {
+ AF_CASES(af);
+ af_inet:
+ assert(len <= 32);
+ mask_r->v4.s_addr= htonl(!len ? 0 : 0xffffffff << (32-len));
+ break;
+ af_inet6: {
+ int i= len/8, j= len%8;
+ unsigned char *m= mask_r->v6.s6_addr;
+ assert(len <= 128);
+ memset(m, 0xff, i);
+ if (j) m[i++]= (0xff << (8-j)) & 0xff;
+ memset(m+i, 0, 16-i);
+ } break;
+ default:
+ unknown_af(af);
+ break;
+ }
+}
+
+int adns__guess_prefix_length(int af, const union gen_addr *addr) {
+ switch (af) {
+ AF_CASES(af);
+ af_inet: {
+ unsigned a= (ntohl(addr->v4.s_addr) >> 24) & 0xff;
+ if (a < 128) return 8;
+ else if (a < 192) return 16;
+ else if (a < 224) return 24;
+ else return -1;
+ } break;
+ af_inet6:
+ return 64;
+ default:
+ unknown_af(af);
+ return -1;
+ }
+}
+
+int adns__addr_match_p(int addraf, const union gen_addr *addr,
+ int netaf, const union gen_addr *base,
+ const union gen_addr *mask)
+{
+ if (addraf != netaf) return 0;
+ switch (addraf) {
+ AF_CASES(af);
+ af_inet:
+ return (addr->v4.s_addr & mask->v4.s_addr) == base->v4.s_addr;
+ af_inet6: {
+ int i;
+ const char *a= addr->v6.s6_addr;
+ const char *b= base->v6.s6_addr;
+ const char *m= mask->v6.s6_addr;
+ for (i = 0; i < 16; i++)
+ if ((a[i] & m[i]) != b[i]) return 0;
+ return 1;
+ } break;
+ default:
+ unknown_af(addraf);
+ return -1;
+ }
+}
+
+void adns__sockaddr_extract(const struct sockaddr *sa,
+ union gen_addr *a_r, int *port_r) {
+ switch (sa->sa_family) {
+ AF_CASES(af);
+ af_inet: {
+ const struct sockaddr_in *sin = CSIN(sa);
+ if (port_r) *port_r= ntohs(sin->sin_port);
+ if (a_r) a_r->v4= sin->sin_addr;
+ break;
+ }
+ af_inet6: {
+ const struct sockaddr_in6 *sin6 = CSIN6(sa);
+ if (port_r) *port_r= ntohs(sin6->sin6_port);
+ if (a_r) a_r->v6= sin6->sin6_addr;
+ break;
+ }
+ default:
+ unknown_af(sa->sa_family);
+ }
+}
+
+void adns__sockaddr_inject(const union gen_addr *a, int port,
+ struct sockaddr *sa) {
+ switch (sa->sa_family) {
+ AF_CASES(af);
+ af_inet: {
+ struct sockaddr_in *sin = SIN(sa);
+ if (port != -1) sin->sin_port= htons(port);
+ if (a) sin->sin_addr= a->v4;
+ break;
+ }
+ af_inet6: {
+ struct sockaddr_in6 *sin6 = SIN6(sa);
+ if (port != -1) sin6->sin6_port= htons(port);
+ if (a) sin6->sin6_addr= a->v6;
+ break;
+ }
+ default:
+ unknown_af(sa->sa_family);
+ }
+}
~ianmdlvl / adns.git / blobdiff